1. Field of the Invention
This invention relates to the field of information networks, and more particularly relates to a method and system for conveying information over a network.
2. Description of the Related Art
Today's networks carry vast amounts of information. High bandwidth applications supported by these networks include streaming video, streaming audio, and large aggregations of voice traffic. In the future, these demands are certain to increase. To meet such demands, an increasingly popular alternative is the use of lightwave communications carried over fiber-optic cables. The use of lightwave communications and their associated protocols provide several benefits, including high bandwidth, ease of installation, and capacity for future growth, although the protocols used in such applications may not be appropriate for use in end-user networks. However, in this new age of data-centric communication networks, the ability to support such user protocols is desirable. Traditionally, two types of telecommunication networks have been developed.
The first type is connection-oriented and is used for the transport of, for example, narrow-band voice traffic, typically carried in time-division multiplexed (TDM) or other synchronous frames. Such networks are, typically, synchronous or plesiochronous networks. The second type of legacy network is connection-less in nature, and is used for the transport of broad-band packet or cell-based data traffic. There is currently a drive towards unified networks which provide end-to-end transport for both voice and data services. However, as there is a well-established voice network base, network operators are naturally reluctant to replace such legacy networks.
Moreover, over the next several years, the growth projected by major service providers in their data (e.g., internet protocol, or IP) networks will only increase the demand on existing infrastructure for bandwidth. The architecture of a typical high-bandwidth backbone network has at least three important properties:
1) Relatively small numbers of nodes, which are interconnected with very high bandwidth links.
2) As the traffic increases, the bandwidth required between these nodes increases, but the number of nodes stays relatively the same.
3) The nodes are widely distributed, often with inter-node distances of well over 1000 km.
Today, as the bandwidth requirements between the core nodes continue to increase, the existing infrastructure is becoming more and more stressed. Beyond current achievable limits, even if it were possible to increase the port speeds of the nodes, the transport systems cannot transport such high data rates using the currently-installed fiber infrastructure without expensive and frequent regeneration. This limitation of economically transporting high data rates over long distances is another important limitation that requires solution.
The ability to support various user protocols across a metropolitan area network (MAN), across the core or in other such situations in which disparate protocols are used, is thus desirable. There is also the need to transport such information in a cost-effective and economical manner. Thus, there is a need to provide an interface between these two types of networks that meets the needs of high-bandwidth applications.